Particle Size Analysis of Shale-rich Mined Clay from Appalachian Ohio

摘要

Clayey soil found in coal mines in Appalachian Ohio is typically used forconstructing Recompacted Soil Liners (RSL) in landfills. The suitability of minedclay for RSL in Ohio is first decided by its clay content. Even though the standardsampling and processing techniques should not produce different grain-sizedistributions, mined clay from Appalachian Ohio is an exception. This discrepancyposes a challenge to the geotechnical engineers who work on prequalification processof RSL material. This paper describes a laboratory investigation conducted on minedclay from Appalachian Ohio to determine how and why the standard sampling and/orprocessing methods affect the grain-size distributions. About a 10 percent decrease inthe clay content was consistently observed in the samples obtained from clayey soilstockpiles, compared to those collected during reverse circulation drilling. It wasdiscovered that the fragments of shale in underclay was responsible for thediscrepancy.